NEW DELHI: Coast Guard patrol vessels intercepted "a suspicious" Pakistani fishing boat in the Arabian Sea in the early hours of January 1, thwarting what the Indian security establishment contends could have been another attempt to unleash mayhem like the 26/11 terror strikes in Mumbai.

The four persons on the largish boat set it ablaze after an hour-long "hot pursuit", which ended with "warning shots" being fired to stop the fishing vessel around 197 nautical miles (365 km) from Porbander, at about 3.50 am on Thursday.

The four-member crew, who "disregarded all warnings" to stop for search, hid themselves in a compartment below the deck and set the boat on fire. "It led to explosions. The nature of the fire clearly indicated the boat was possibly carrying explosives. The boat or its crew could not be saved due to the darkness, bad weather and strong winds. It sank in the same spot," said a defence ministry official.

The entire operation began after intelligence inputs on December 31 that a fishing boat from Keti Bunder near Karachi was planning "some illicit transaction" in the Arabian Sea, which led the technical intelligence agency NTRO to alert the Coast Guard.

"Coast Guard Dornier aircraft first located and then continuously tracked the fishing boat. A patrol vessel, ICGS Rajratan, was then diverted and intercepted the boat around midnight on December 31 in position 365 km west-south west of Porbander," said the official.

"The Coast Guard ship warned the boat to stop for further investigation and search of crew and cargo. The boat, however, increased speed and tried to escape away from the Indian side of maritime boundary (India's exclusive economic zone stretches to 200 nautical miles from coast). The fishing vessel stopped only after ICGS Rajratan fired warning shots at it after a hot pursuit for an hour," he added.